DNN 3 Newsletter - Selecting Role not working


I've got DNN 3.2 installed and everything seems fine, except for part of the Newsletter module.

I can add a list of Users in the List box, and all the emails go out. I've registered Users with these same email adresses, and when I select 'Registered Users', the system says they all go out, but only one arrives.

I'm using emails on 4 different domains, including one on the site domain and one on hotmail.com

Emails go out to all of these domains when they are in the List box, but only the User on the site domain gets the email when the Registered User role is checked. The system reports they all go, but only one arrives.

All the right entries seem to be there in the aspnet_ and other User tables in the database. I can't 'see' the emails going out, so I haven't a clue what else to check.

Anyone have ideas?